The proposed research is intended to be a pilot study leading to research to distinguish between three possible effects of delta-9-THC on rat learning and memory. THC may affect measured retention by interfering with memory storage if the drug is administered during training, or memory retrieval if the drug is administered during a retention test. THC may also affect measured retention through a state dependent effect which depends on whether the state (drugged or not drugged) during training and retention test is the same or different. These three hypotheses can be independently tested in a 2x2 factorial analysis of variance design composed of drug (D) and no drug (ND) during training and D and ND during retention test. A memory storage effect implies a main effect of drug during training; a memory retrieval effect implies a main effect of drug during retention test; a state dependent effect implies an interaction between drug used during training and test. Since almost all THC studies with rats have used large dosage levels that are probably aversive, the proposed pilot research consists of 2 experiments to find non-aversive but effective dosage levels of THC.